Lamda Expression: It is an unnamed method written in the place of delegate instance. The symbole => is called Lamda operator. LINQ :- Linq(Language Integrated Query) integrates query syntax inside the c# programming language. It is collection of standard query operators which provides query facility in .NET framework language like c#, VB.NET. There is no difference in performance because after compile they generate same IL code for the same query. Code in Linq :- var query = from e in EmployeeList where e.Age > 24 select e; Same code in Lamda Expression:- var query1 = EmployeeList.Where(e => e.Age > 24); LINQ Code Sample :- 1. var query = from c in CustomerList join p in PurchaseList on c.ID equals p.CustomerId select c.Name + " " + p.ItemName 2. var query2 = (from e in EmployeeList where e.Name.StartsWith("a") select e).ToList(); 3. var query3 = from c in CustomerList join p in PurchaseList on c.Id equals p.CustomerId into Cart from c in Cart.DefaultIfEmpty() select new {custName=c.Name, Price=cp==null?(decimal?) :cp.Price }; Lamda Expression Code Sample :- 1. var query= Enumerable .Range(1, 100) .Where(x => (x % 2) == 0) .ToList(); 2. var query2 = EmployeeList.Where(e=> e.Name.StartsWith("a")).ToList(); 3. var query 3 = CustomerList .GroupBy (o => o.CustomerID) .Select (o => new { CustomerID = o.Key, TotalOrders = o.Count () })

LINQ use Lamda expression (syntax) to execute query (function).